> Boost is a monolithic release, it might indeed be good to think about how
> the outcome of the CMake discussion interacts with the other profound
> change that has been worked on not so long ago: to model and reduce
> dependencies between libraries and break the monolithic structure.

That is also a bit beside my point. It doesn't matter for this use case
whether Boost is monolithic or not; it could be that only a few of the
libraries have in fact been installed. What matters is that the directory
structure is

$BOOST_ROOT/
libs/
hana/
lib2/
lib3/

and that the user wishes to build, test and optionally install one (and then
optionally another) of the libraries.